Measuring the Labile and Recalcitrant Pools of Carbon and Nitrogen in Forested and Agricultural Soils: A Study under Tropical Conditions
, Joseph Elias Rodrigues Mikhael 2, Fernando Oliveira Franco 3, Luna Monique Fonseca Santana 1 and Beno Wendling 1Round 1
Reviewer 1 Report
general comments:
This paper measures and describes labile and recalcitrant pools of carbon and nitrogen in forested and agricultural soils in Brazilian tropics. I think that most reliable patterns found in this study are that soils in forested lands are richer in soil organic materials than soils in agricultural lands, and that surface layers are richer in soil organic materials than subsurface layers, both of which are well-known text-book patterns. Although the authors measured five properties of soils (TOC, TON, labile-C, SMB-C, and SMB-N), the quantitative patterns in different soils were very similar among them. The conditions and histories of seven soils are very specific, except the difference between forests and agricultural conditions, making the results of this study less applicable to soils in other regions or under different conditions.
specific comments:
P. 2, L. 45: What did you do with four replications of soils? Did you mix the replication in soil analyses or were they separately analyzed?
P.4, L.8: TOC is missing from the list of variables for PCA, while TOC is listed in the caption of Fig. 1.
Figure 1: I imagined that four square points represent for surface and subsurface soils in FO and FC, five red points represent for surface soils in FP, UP, CC, SC, CS, and five black points represent for subsurface soils in FP, UP, CC, SC, CS. Is it right? It should be explicitly described in the text and caption.
P.4, L.20: The first sentence of the paragraph can be more explicit.
P.5, L.1-2: I do not understand the first sentence.
P.5, L.3: I do not think that SMB-N and SMB-C had distinct tendencies from those for other variables. The differences are relative and quantitative. The correlations between two variable groups may be high because all the vectors are pointing to the left.
P.5, L.4: What do you mean by "fixed"?
Table 2: I do not think this table provide additional information to what Figure 1 provides.
Figure 2: This figure is confusing because both TOC and TON are presented in one graph and the same letters (for Tukey test) are used for TOC and TON. Moreover, the differences in TON become unclear when TONs are presented with TOC. The variations in the data should be shown in graph (e.g. error bars or box plots, if they exist).
P.6, L.5: Does Figure 2 show "recalcitrant" TOC and TON?
Table 3: Why do some numbers have letters while some other do not?
Figure 2, 3, and 4: The structure of the graphs should be consistent, and consistent textures should be used.
P.7, L.3-4: FC, not CC, have the highest SMB-N and SMB-C. Rephrase this sentence.
P.8, subsection 3.5: I think that this part is almost a repetition of the previous parts.
Author Response
Dear Editor/Reviewer,
We are resubmitting the manuscript “Measuring the Labile and Recalcitrant Pools of Carbon and Nitrogen in Forested and Agricultural Soils: A Study Under Tropical Conditions”, by Risely Ferraz Almeida, Joseph Elias Rodrigues Mikhael, Fernando Oliveira Franco, Luna Monique Fonseca Santana and Beno Wendling for consideration for publication in Forest.
We appreciate the time of the Editor and reviewer#1 to exam this manuscript and make thoughtful suggestions. The editions in the manuscript were approved by all authors. The suggestions from the Reviewers #1, are highlighted (blue) in the Manuscript and answered below.
SPECIFIC COMMENTS
Reviewer: “This paper measures and describes labile and recalcitrant pools of carbon and nitrogen in forested and agricultural soils in Brazilian tropics. I think that most reliable patterns found in this study are that soils in forested lands are richer in soil organic materials than soils in agricultural lands, and that surface layers are richer in soil organic materials than subsurface layers, both of which are well-known text-book patterns. Although the authors measured five properties of soils (TOC, TON, labile-C, SMB-C, and SMB-N), the quantitative patterns in different soils were very similar among them. The conditions and histories of seven soils are very specific, except the difference between forests and agricultural conditions, making the results of this study less applicable to soils in other regions or under different conditions.”
Authors: “Dear reviewer, we are glad to know that you like our MS.”
Reviewer: “P. 2, L. 45: What did you do with four replications of soils? Did you mix the replication in soil analyses or were they separately analyzed?”
Authors: “Dear reviewer, we did not mix the samples. The four samples were used to run the statistics tests.”
Reviewer: “P.4, L.8: TOC is missing from the list of variables for PCA, while TOC is listed in the caption of Fig. 1.”
Authors: “Dear reviewer, you are correct. We edited and added TOC in the list of variables. Thank you for your suggestions.”
Reviewer: “Figure 1: I imagined that four square points represent for surface and subsurface soils in FO and FC, five red points represent for surface soils in FP, UP, CC, SC, CS, and five black points represent for subsurface soils in FP, UP, CC, SC, CS. Is it right? It should be explicitly described in the text and caption.”
Authors: “Dear reviewer, thank for your observation. We edited and explained that information more clearly in MS. Thank you for your suggestions.”
Reviewer: “The first sentence of the paragraph can be more explicit.”
Authors: “Dear reviewer, we edited that information in MS. Thank you for your suggestions.”
Reviewer: “I do not understand the first sentence.”
Authors: “Dear reviewer, we edited that information in MS. Thank you for your suggestions.”
Reviewer: “I do not think that SMB-N and SMB-C had distinct tendencies from those for other variables. The differences are relative and quantitative. The correlations between two variable groups may be high because all the vectors are pointing to the left.”
Authors: “Dear reviewer, your observation is correct but SMB for both C and N present a variance associated to CP2 (Table 2). We describe this result clearly in MS. Thank you for your suggestions.”
Reviewer: “What do you mean by "fixed"?”
Authors: “Dear reviewer, it means associated. We changed that expression to be clear the sentence”
Reviewer: “Table 2: I do not think this table provide additional information to what Figure 1 provides.”
Authors: “Dear reviewer, we understand you point of view. However, we would like to keep this table because it brings information of values variance and mean to each variable. We hope you can understand our point of view.”
Reviewer: “Figure 2: This figure is confusing because both TOC and TON are presented in one graph and the same letters (for Tukey test) are used for TOC and TON. Moreover, the differences in TON become unclear when TONs are presented with TOC. The variations in the data should be shown in graph (e.g. error bars or box plots, if they exist).
Authors: “Dear reviewer, we understand you point of view. We separated the figures according to variables, TOC and TON. The letters of Tukey-test were represented for each soil and variable and is needed to used different letter.”
Reviewer: “Figure 2: This figure is confusing because both TOC and TON are presented in one graph and the same letters (for Tukey test) are used for TOC and TON. Moreover, the differences in TON become unclear when TONs are presented with TOC. The variations in the data should be shown in graph (e.g. error bars or box plots, if they exist).
Authors: “Dear reviewer, we understand you point of view. We separated the figures according to variables, TOC and TON. The letters of Tukey-test were represented for each soil and variable and is needed to used different letter.”
Reviewer: “Figure 2: This figure is confusing because both TOC and TON are presented in one graph and the same letters (for Tukey test) are used for TOC and TON. Moreover, the differences in TON become unclear when TONs are presented with TOC. The variations in the data should be shown in graph (e.g. error bars or box plots, if they exist).”
Authors: “Dear reviewer, we understand you point of view. We separated the figures according to variables, TOC and TON. The letters of Tukey-test were represented for each soil and variable and is needed to used different letter.”
Reviewer: “Does Figure 2 show "recalcitrant" TOC and TON?”
Authors: “Dear reviewer, we are correct. The TOC and TON are not recalcitrant part, exclusively. We edited this part in MS.”
Reviewer: “Table 3: Why do some numbers have letters while some other do not??”
Authors: “Dear reviewer, letters were added when there was no statistics difference.”
Reviewer: “Table 3: Why do some numbers have letters while some other do not??”
Authors: “Dear reviewer, letters were added when there was statistics difference.To clarify this situation a sentence was added in Table explaining it”
Reviewer: “P.7, L.3-4: FC, not CC, have the highest SMB-N and SMB-C. Rephrase this sentence.”
Authors: “Dear reviewer, perfect observation. We edited this part. Thank you.”
Reviewer: “P.8, subsection 3.5: I think that this part is almost a repetition of the previous parts.”
Authors: “Dear reviewer, we understand you point of view. We would like to keep this part because this is a balance of stocks/losses of carbon and nitrogen labile and recalcitrant) for Oxisol (Unfertilized Pasture-UP, Fertilized Pasture-FP) and Cambisol (Pasture, Coast Cross-CC, Sugarcane-SC and corn silage-CS). We hope you can understand our point of view.”
Reviewer 2 Report
Review –Forests, May 2019
Ferraz de Almeida et al., “Measuring the labile and recalcitrant pools of carbon and nitrogen in forested and agricultural soils: a study under tropical conditions”.
General comments
This study investigated the suggested influence of agricultural practices on forms of soil carbon and nitrogen in tropical soils. It is generally well-written and employs sound science. The biggest issue is that the authors frequently refer to differences between management and soil levels even though the results do not appear to be significantly different. It is okay to mention a common trend, but make it clear that not all of the differences discussed are statistically significant. Along these lines, the authors regularly claim a direct relationship between land use and soil nutrient content. Substantial caution needs to be employed throughout to clarify that these are correlations and not differences resulting from direct manipulations. I would recommend including modifying the text throughout with terms such as “suggests” or “implies” to soften claims in the results and discussion.
Additionally, the study design comparing the forested systems to the agricultural sites needs explanation early on in the abstract and introduction. This is generally a good design, and should receive more attention early in the manuscript.
If the issues discussed above and outlined below (see detailed comments) are addressed, I believe this paper will make a strong contribution to this journal.
Detailed comments, by page number
1. Page 1 (Abstract): Carbon is introduced at the beginning of the abstract but nitrogen is not mentioned. Please justify nitrogen as well here
2. Page 1 (Abstract): As mentioned in general comments, introduce why the forested sites were studied for comparison in a more straightforward way.
3. Page 1 (Abstract): Three aims mentioned in the abstract and introduction are not really independent aims, in particular the first aim. Suggest combining these in a more succinct statement.
4. Page 1 (Abstract): The use of abbreviations seems unnecessary here in the abstract.
5. Page 1 (Abstract): Clarify sentence beginning with “Results showed that labile and recalcitrant pools presented different stocks between soil layers being more…”. Possibly just a run-on, but the meaning is lost here.
6. Page 2 (1st paragraph): Sentence beginning with “The sum of both pools, with different cycling timescales…” is awkward and unclear.
7. Page 2 (2nd paragraph): Sentence beginning with “SMB demonstrates a strong capacity to detect…”. Do you mean “labile carbon” instead of “SMB”?
8. Page 2 (4th paragraph): Text stating “HU, following FA or HA” should instead state “HU, followed by FA or HA”
9. See item #3 above regarding adjusting and/or combining aims in the introduction and abstract
10. Page 2 (Section 2.1): How were soils sampled? How much was collected, what tool was used, how were replicate locations determined?
11. Page 3 (Paragraph 1): text stating “for N, P2O5, and K2O until 2002”, what was N-P-K of this application? In same paragraph, what form of N was applied for the “top dressed” application in 2002?
12. Page 3 (Paragraph 2): States “improper management”. How so? Please elaborate if important.
13. Page 3 (Paragraph 2): Text stating “from all areas can be found [17]” should state “from all areas can be found in [17]
14. Page 4 (Paragraph 4): What type of Tukey test was used?
15. Page 4 (Figure 1 caption): Put color code (e.g. “black”, “red”, “white”) in parentheses
16. Page 5 (1st paragraph and first line): What does this sentence refer to? What is higher?
17. Page 5 (Section 3.2): Confusing first sentence with regards to what is being compared with what. Forest (FO) is greater than UP but not FP at the surface. Make sure to specify what is being compared here and throughout.
18. Page 5 (Figure 2 caption): “Cambisol (Forest-FC, Pasture, …)”, “Pasture” is not followed by an abbreviation.
19. Page 6 (1st paragraph): “Therefore land use had a direct influence”- this language is too strong for a comparison study. Need to nuance with e.g., “suggests” and remove “direct”
20. Page 6 (Section 3.3): “the lowest concentration at all the humic substance”- “at all” should be changed to “of”
21. Page 6 (section 3.3): “while FO represented the best way” is awkward and again too strong of a claim given it is a comparison study
22. Page 6 (Table 3): The column for Cambisol HU averages do not have letters indicating significant differences. Same with HU and HA averages for surface and subsurface across both soil types
23. Page 6 (Section 3.4 2nd paragraph): The forest treatment not significantly different from FP for labile-C stocks. Please correct.
24. Page 6 (Section 3.4 2nd paragraph): “Interestingly, CC similarly”- why is this similar?
25. Page 6 (Section 3.4 3rd paragraph): SMB-C and SMB-N did not decrease with depth significantly for all management systems- UP and SC are the same.
26. Page 6 (Section 3.4 4th paragraph): Differences mentioned in this first sentence are not significantly different (e.g., FO and FP are the same)
27. Page 7 (Figure 4): Order of letters indicating significance is switched- a little confusing
28. Page 8 (Table 4): This is a great table, but please add in the table description the word “suggested” since this is a comparison study. Also, are these differences all significant?
29. Page 8 (1st paragraph of discussion): Add in the word “generally” before “higher labile-C and SMB-C concentrations compared to…”
30. Page 8 (2nd paragraph of discussion): First sentence here is awkward and confusing. Please revise.
31. Page 8 (3rd paragraph of discussion): Add in “likely” before “due to the specific management of the area”
32. Page 8 (3rd paragraph of discussion): Add in “suggested” or something similar before “high C and N losses due to the prevalence of plowing…”
33. Page 8 (4th paragraph of discussion): Replace “tend” with “appear” or something similar. Also, specify if you are referring to the surface soil layer here.
34. Page 9 (1st paragraph): This whole paragraph is redundant with 1st paragraph of discussion. Suggest combining or removing.
35. Page 9 (2nd paragraph): Language in paragraph, especially regarding “dynamism”, makes it seem like you directly assessed these qualities. Clarify to indicate this is a general trend reported in the literature.
36. Page 9 (4th paragraph ): Remove “-labile” following “N” at the end of the paragraph
37. Page 9 (5th paragraph): Remove “This happens because”
38. Page 9 (6th paragraph): First sentence is a run-on- please revise.
Author Response
Dear Editor/Reviewer#2,
We are resubmitting the manuscript “Measuring the Labile and Recalcitrant Pools of Carbon and Nitrogen in Forested and Agricultural Soils: A Study Under Tropical Conditions”, by Risely Ferraz de Almeida, Joseph Elias Rodrigues Mikhael, Fernando Oliveira Franco, Luna Monique Fonseca Santana and Beno Wendling for consideration for publication in Forest.
We appreciate the time of the Editor and reviewer#1 to exam this manuscript and make thoughtful suggestions. The editions in the manuscript were approved by all authors. The suggestions from the Reviewers #2, are highlighted (green) in the Manuscript and answered below.
SPECIFIC COMMENTS
Reviewer: “This study investigated the suggested influence of agricultural practices on forms of soil carbon and nitrogen in tropical soils. It is generally well-written and employs sound science. The biggest issue is that the authors frequently refer to differences between management and soil levels even though the results do not appear to be significantly different. It is okay to mention a common trend, but make it clear that not all of the differences discussed are statistically significant. Along these lines, the authors regularly claim a direct relationship between land use and soil nutrient content. Substantial caution needs to be employed throughout to clarify that these are correlations and not differences resulting from direct manipulations. I would recommend including modifying the text throughout with terms such as “suggests” or “implies” to soften claims in the results and discussion. Additionally, the study design comparing the forested systems to the agricultural sites needs explanation early on in the abstract and introduction. This is generally a good design, and should receive more attention early in the manuscript. If the issues discussed above and outlined below (see detailed comments) are addressed, I believe this paper will make a strong contribution to this journal.”
Authors: “Dear reviewer, we thankful for your words and concert about our study. We followed all your suggestions to make our story clear. Thank you very much for your suggestions and editions.”
Reviewer: “Page 1 (Abstract): Carbon is introduced at the beginning of the abstract but nitrogen is not mentioned. Please justify nitrogen as well here”
Authors: “Dear reviewer, we edited this part and mentioned N in the abstract as you suggestions. Thank you.”
Reviewer: “Page 1 (Abstract): As mentioned in general comments, introduce why the forested sites were studied for comparison in a more straightforward way.”
Authors: “Dear reviewer, thank you for your observation. We edited this part and added in sentence to explain Forested soil as an appropriate form of soil conservation in tropical that presents levels adequate of carbon and nitrogen stocks and biological condition in soil. We are thankful.”
Reviewer: “Page 1 (Abstract): Three aims mentioned in the abstract and introduction are not really independent aims, in particular the first aim. Suggest combining these in a more succinct statement.”
Authors: “Dear reviewer, thank you for your observation. We edited our objective and edited according to your suggestion”
Reviewer: “Page 1 (Abstract): The use of abbreviations seems unnecessary here in the abstract
Authors: “Dear reviewer, thank you for your observation. All abbreviations were deleted in abstract according to your suggestion”
Reviewer: “Page 1 (Abstract): Clarify sentence beginning with “Results showed that labile and recalcitrant pools presented different stocks between soil layers being more…”. Possibly just a run-on, but the meaning is lost here”
Authors: “Dear reviewer, thank you for your observation. This sentence was edited.”
Reviewer: “Page 2 (1st paragraph): Sentence beginning with “The sum of both pools, with different cycling timescales…” is awkward and unclear.”
Authors: “Dear reviewer, thank you for your suggestion. We edited this sentence to leave clear the message.”
Reviewer: “Page 2 (2nd paragraph): Sentence beginning with “SMB demonstrates a strong capacity to detect…”. Do you mean “labile carbon” instead of “SMB”?.”
Authors: “Dear reviewer, thank you for your suggestion. We edited this sentence to leave clear the message of impact of SMB and labile-C on labile carbon in soil.”
Reviewer: “Page 2 (4th paragraph): Text stating “HU, following FA or HA” should instead state “HU, followed by FA or HA”
Authors: “Dear reviewer, thank you for your suggestion. We edited this sentence to leave clear the message.”
Reviewer: “See item #3 above regarding adjusting and/or combining aims in the introduction and abstract”
Authors: “Dear reviewer, thank you for your suggestion. We edited according to abstract.”
Reviewer: “Page 2 (Section 2.1): How were soils sampled? How much was collected, what tool was used, how were replicate locations determined?”
Authors: “Dear reviewer, thank you for your suggestion. We clarified the information about soil collection.”
Reviewer: “Page 3 (Paragraph 1): text stating “for N, P2O5, and K2O until 2002”, what was N-P-K of this application? In same paragraph, what form of N was applied for the “top dressed” application in 2002?”
Authors: “Dear reviewer, thank you for your suggestion. We clarified the information about fertilizer application.”
Reviewer: “Page 3 (Paragraph 1): text stating “for N, P2O5, and K2O until 2002”, what was N-P-K of this application? In same paragraph, what form of N was applied for the “top dressed” application in 2002?”
Authors: “Dear reviewer, thank you for your suggestion. We clarified the information about fertilizer application.”
Reviewer: “Page 3 (Paragraph 2): States “improper management”. How so? Please elaborate if important.”
Authors: “Dear reviewer, thank you for your suggestion. We clarified the information about improper management, fertilization absence.”
Reviewer: “Page 3 (Paragraph 2): Text stating “from all areas can be found [17]” should state “from all areas can be found in [17]”
Authors: “Dear reviewer, this edition was made.”
Reviewer: “Page 3 (Paragraph 2): Text stating “from all areas can be found [17]” should state “from all areas can be found in [17]”
Authors: “Dear reviewer, this edition was made.”
Reviewer: “Page 4 (Figure 1 caption): Put color code (e.g. “black”, “red”, “white”) in parentheses”
Authors: “Dear reviewer, this edition was made. Thank you!”
Reviewer: “Page 5 (1st paragraph and first line): What does this sentence refer to? What is higher?”
Authors: “Dear reviewer, we re-written this sentence to make the sentence clear to readers. Thank you!”
Reviewer: “Page 5 (Section 3.2): Confusing first sentence with regards to what is being compared with what. Forest (FO) is greater than UP but not FP at the surface. Make sure to specify what is being compared here and throughout.
Authors: “Dear reviewer, we re-written this sentence to make the sentence clear to readers. Thank you!”
Reviewer: “18. Page 5 (Figure 2 caption): “Cambisol (Forest-FC, Pasture, …)”, “Pasture” is not followed by an abbreviation.”
Authors: “Dear reviewer, we checked this abbreviation. Thank you!”
Reviewer: “19. Page 6 (1st paragraph): “Therefore land use had a direct influence”- this language is too strong for a comparison study. Need to nuance with e.g., “suggests” and remove “direct”; 20 “Page 6 (Section 3.3): “the lowest concentration at all the humic substance”- “at all” should be changed to “of””; “21. Page 6 (section 3.3): “while FO represented the best way” is awkward and again too strong of a claim given it is a comparison study”; “ 29. Page 8 (1st paragraph of discussion): Add in the word “generally” before “higher labile-C and SMB-C concentrations compared to…”; “30. Page 8 (2nd paragraph of discussion): First sentence here is awkward and confusing. Please revise.”; “31. Page 8 (3rd paragraph of discussion): Add in “likely” before “due to the specific management of the area”; “ 33. Page 8 (4th paragraph of discussion): Replace “tend” with “appear” or something similar. Also, specify if you are referring to the surface soil layer here.”; “35. Page 9 (2nd paragraph): Language in paragraph, especially regarding “dynamism”, makes it seem like you directly assessed these qualities. Clarify to indicate this is a general trend reported in the literature.”; “36. Page 9 (4th paragraph): Remove “-labile” following “N” at the end of the paragraph”; 37. Page 9 (5th paragraph): Remove “This happens because”; “38. Page 9 (6th paragraph): First sentence is a run-on- please revise.”
Authors: “Dear reviewer, these information were added. We agreed with your point of view and grammar suggestions. Thank you!”
Reviewer: “27. Page 7 (Figure 4): Order of letters indicating significance is switched- a little confusing”
Authors: “Dear reviewer, figure 4 was changed according to suggestion of another reviewer. We hope this changing agree with your suggestion. Thank you!”
Reviewer: “22. Page 6 (Table 3): The column for Cambisol HU averages do not have letters indicating significant differences. Same with HU and HA averages for surface and subsurface across both soil types”; “ 28. Page 8 (Table 4): This is a great table, but please add in the table description the word “suggested” since this is a comparison study. Also, are these differences all significant?”
Authors: “Dear reviewer, we did not added letters for these variables because there was no difference. We added a sentence in table to explain it. The information in Table 4 was not compared by statistics test. Thank you!”
Reviewer: “23. Page 6 (Section 3.4 2nd paragraph): The forest treatment not significantly different from FP for labile-C stocks. Please correct.”; “24. Page 6 (Section 3.4 2nd paragraph): “Interestingly, CC similarly”- why is this similar?”
Authors: “Dear reviewer, we checked these information and edited the sentence. Thank you!”
Round 2
Reviewer 1 Report
Although I found some improvements in the revised manuscript, I am still not convinced that the novelty and generality are high enough for international journals. At least, authors should mention clearly and explicitly what are the novelty and generality in this paper.
specific comments: p.
3, l. 6-7: I do not understand the sentence "The soil containing corn
(Zea 6 mays L.) silage (CS) was planted from 1986 using two annual crops
and the addition of fertilizer." p.5, l.1: If labile C is included in TOC, this sentence is quite natural (it need not to be mentioned). p.6,l.27: Is the phrase "which equates to an increase of 21% compared to FP" right? p.6, l. 36 - p.7, l.3: These three sentences overlap with the information given by Fig.4 and preceding sentences.
Author Response
June, 2019
Dear Editor/Reviewer,
Forest
Dear Editor/Reviewer,
We are resubmitting the manuscript “Measuring the Labile and Recalcitrant Pools of Carbon and Nitrogen in Forested and Agricultural Soils: A Study Under Tropical Conditions”, by Risely Ferraz Almeida, Joseph Elias Rodrigues Mikhael, Fernando Oliveira Franco, Luna Monique Fonseca Santana and Beno Wendling for consideration for publication in Forest. We appreciate the time of the Editor and reviewer to exam this manuscript and make thoughtful suggestions. The editions in the manuscript were approved by all authors. The suggestions from the Reviewers are highlighted (green) in the Manuscript and answered below.
REVIEWER COMMENTS
Reviewer: “Although I found some improvements in the revised manuscript, I am still not convinced that the novelty and generality are high enough for international journals. At least, authors should mention clearly and explicitly what are the novelty and generality in this paper.”
Authors: “Dear reviewer, thank you for your suggestions and editions. We believe that our study brings important outcome because regions located in the tropical climate zones suffer the greatest rainfall-related soil erosion. The Global Assessment of Soil Degradation (GLASOD) commissioned by the United Nations Environment Program estimated that nearly 2 billion ha (22.5 percent) of agricultural land, pasture, forest and woodland had been degraded since mid-twentieth century. For example, Brazil has approximately 200 million hectares of native or implanted pastures, with 130 million hectares are degraded and requiring some intervention to reverse this state. We demonstrate an alternative to recover degraded areas in our study with adequate fertilization management systems we can recover degraded areas with low levels of recalcitrant carbon and nitrogen pools in tropical conditions. Fertilized pasture exhibited an increase of 16 and 2% in recalcitrant carbon and nitrogen pools compared to forested soil, respectively. We also understand that more researches are a necessary to keep looking for new approaches that will likely require a combination of soil management. We are developing new studies to better understand the stocks of carbon and nitrogen in soil. We hope you understand how important is our study to conservation of soil. We are thankful for your time that you spent reading our manuscript.”
SPECIFIC COMMENTS:
Reviewer: “p. 3, l. 6-7: I do not understand the sentence "The soil containing corn (Zea 6 mays L.) silage (CS) was planted from 1986 using two annual crops and the addition of fertilizer."
Authors: “Thank you for your questions. We explain the sentence with information of annual production of corn in Brazil.”
Reviewer: “p.5, l.1: If labile C is included in TOC, this sentence is quite natural (it need not to be mentioned).”
Authors: “We understand you point of view. We deleted this part on Manuscript. Thank you.”
Reviewer: “p.6,l.27: Is the phrase "which equates to an increase of 21% compared to FP" right?”
Authors: “Yes. It is right. The sentence “Forest treatment provided the highest labile-C stocks with a mean of 2.37 g kg−1 (surface) in Latosol, which equates to an increase of 21% compared to FP” is right. FP means fertilized pasture.”
Reviewer: “p.6, l. 36 - p.7, l.3: These three sentences overlap with the information given
by Fig.4 and preceding sentences.”
Authors: “We checked that suggestion and corrected it. The information on Figure 4 is related to carbon and nitrogen in soil microbial biomass, and the theses three sentences is related to recalcitrant carbon and nitrogen. Thank you for you concert about our Manuscript”
Author Response File: 
Author Response.docx
